I was always taught that when rolling it should be silent, and when breakfalling you should make alot of noise with the slap of your hand as it takes the shock away from the spine.
I told a student recently that the more noise you make when you breakfall the less damage you will do to yourself. the next time he did a breakfall not only did he slap the mat, but he also shouted lol
must learn to be more explicit with words when teaching.
Kev